Silver Seal MS340G1 MicroSleeve Crankshaft Rear Seal Surface Repair Sleeve Ground 1 Undersized

The Silver Seal MS340G1 MicroSleeve is a precision crankshaft rear seal surface repair sleeve designed for crankshafts that have been ground one undersize (G1). This sleeve provides a cost-effective solution to restore a worn or grooved crankshaft sealing surface, eliminating the need for costly crankshaft replacement.

Over time, the oil seal wears a groove into the crankshaft flange, causing persistent leaks even after seal replacement. The Silver Seal MicroSleeve installs over the worn sealing area of the crankshaft, creating a new, smooth sealing surface that allows the rear main oil seal to function properly.

Key Features:

• G1 (Ground 1 Undersized) — engineered specifically for crankshafts that have been ground one undersize; not for use on standard (unground) crankshafts
• Press-fit installation onto the crankshaft rear seal journal
• Restores a fresh, precision sealing surface without crankshaft removal or replacement
• Compatible with the same standard-size rear main oil seal — minimal buildup to sealing OD
• Manufactured by Silver Seal Products Co., a trusted engine parts supplier since 1959
• Part of Silver Seal's 300-series crankshaft seal surface sleeve line

The MS340G1 is an economical repair option for professional engine builders and machine shops dealing with oil leaks caused by a worn rear crankshaft seal surface on ground crankshafts. An appropriate Silver Seal MST-series installation tool is recommended for proper fitment.